Hi! > > On Fri 2021-10-01 13:56:57, Suren Baghdasaryan wrote: > > > While forking a process with high number (64K) of named anonymous vmas the > > > overhead caused by strdup() is noticeable. Experiments with ARM64 > > Android > > > > I still believe you should simply use numbers and do the > > numbers->strings mapping in userspace. We should not need to optimize > > strdups in kernel... > > Here are complications with mapping numbers to strings in the userspace: > Approach 1: hardcode number->string in some header file and let all > tools use that mapping. The issue is that whenever that mapping > changes all the tools that are using it (including 3rd party ones) > have to be rebuilt. This is not really maintainable since we don't > control 3rd party tools and even for the ones we control, it will be a > maintenance issue figuring out which version of the tool used which > header file. 1a) Just put it into a file in /etc... Similar to header file but easier... > Approach 2: have a centralized facility (a process or a DB) > maintaining number->string mapping. This would require an additional > request to this facility whenever we want to make a number->string > conversion. Moreover, when we want to name a VMA, we would have to I see it complicates userspace. But that's better than complicating kernel, and I don't know what limits on strings you plan, but considering you'll be outputing the strings in /proc... someone is going to get confused with parsing. Pavel -- http://www.livejournal.com/~pavelmachek
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